Fifteen-year-olds in Hong Kong, Finland, and Korea excel in applying the science and math concepts they've learned, whereas U.S. students trail their peers in much of the industrial world. That's one lesson from the latest results of an international test that goes beyond the usual assessment of what students know.

The Program for International Student Assessment (PISA) is part of an ongoing effort to compare the educational performance of students around the world. Unlike other international tests, which have focused on students' knowledge of specific concepts, the PISA test measures how students apply the sum of their education to new problems. The test, first given in 2000, is coordinated by the Organisation for Economic Co-operation and Development (OECD) in Paris.

The 2003 PISA test was taken by 270,000 students in 41 countries. Students had 2 hours to complete the exam, which consisted largely of open-ended or short answer questions. A sample math question asks students to figure out how much money they lose by exchanging their South African rands for Singapore dollars given fluctuating exchange rates. In the science section, students must decide what role scientific research should play in policy decisions regarding the ozone layer.

Hong Kong students placed first in math in the test, and Finland held the top spot in science. The ranking of individual countries changed little from the previous test in 2000, although Poland, Germany, and the Czech Republic did significantly better the second time around. Wealthier countries tended to place higher on the PISA charts, although students in Korea, with a national income 30% below the average of most of the participating countries, placed third in math and fourth in science. U.S. students stood 24th in math and 23rd in science, similar to their rankings in 2000.

"What these results say is that a student in Finland will have an easier time using his math and science knowledge to make sense of an unfamiliar situation than will a student from the U.S.," says Thomas Romberg, a math educator at the University of Wisconsin, Madison. As for PISA's impact in the U.S., says Larry Suter, deputy director of the Division of Research, Evaluation, and Communication at the National Science Foundation, state assessments should be reevaluated to gauge the application of knowledge, not just retention, as a marker of student progress.